Oxygen emergency apparatus with closed respiratory circuit



Jan.2s,193s. MHAUSMANN .-'2L106934 OXYGEN EMERGENCY APPARATUS WITH CLOSED RESPIRATORY CIRCUIT Maw Hausmann nvnfor By His Aorneys Jan. 25, 1938. M. HAUSMANN OXYGEN EMERGENCY-APPARATUS WITH CLOSED RESPIRATORY CIRCUIT Filed oct, 2'1, 193e 2. Sheets-Sheet 2 figs Max Hausmann' nvenfol' By His Attorneys Patented Join. 25, 1938 UNITED STATES PATENT OFFICE f many; assigner to I. G. Farbenindustrle Aktiengesellschaft, Frankfort-on-the-Main, Germany Applicaties october- 21, isst, serial No. 106,129

- En Germany December 5, w29

3 claims.

This invention relates to oxygen emergency apparatus with closed respiratory circuit.

In closed respirators inwhich all the exhaled air is passed for purlcation through a mass absorbing carbon dioxide (pbtash cartridge) it has already been proposed to overcome the considerable resistance that said mass offers to the'circulation of the respiratory air by causing expansion of oxygen delivered under pressure from the oxygen flask at least partly inthe respiratory circuit, thus producing an injector pump action. However,'when oxygen is used which has been generated from mixtures of chemical substances, for instance of such containing chlorates or perohlorates as the oxYgen-yielding constituents. andirom which oxygen is generated in an automatically progressive reaction after initial heating, in which case, if any, then only a slight drop in pressure due to expansion is available, the diminution of the resistance ci the absorption cartridge obtained by utilizing the injector action of such oxygen is tfouncl to be inadequate.

On the other hand it has been ascertained in accordance with the present invention that it is possible to utilize the foregoing injector action' with advantage for the construction of light and simple closed oxygen respirators in which the oxygenis generated in a manner known per se, (sector example, U. S. Patent 1,408,757 or British Patent 341,975) from a mass giving 0H a constant current air tobe passed through the carbon dioxide absorption cartridge in each respiratory period,

since temporarily at least, a CO2 concentration in the inhaled air somewhat exceeding the normall is not harmful to the wearer of the apparatus, which is merely intended to enable him to escape from the danger zone.

In accordance with the present invention therefore, the exhaled air is deliberately only partly puried, the carbon dioxide absorption cartridge being placed in the secondary current, pulsating respiration being` applied, thus promotingthe circulation of the volume of air in the secondary current only by the injector action oi.' the freshly introduced oxygen. By this means it has been found possible to eliminate when necessary the customary, expensive and bulky form of construction of the CO2 absorption cartridge with metal jacket and wire screens of various forms. which'was necessitated only by the eiiort to re- (Ci. 12S-4191) duce as far as possible the resistance to circulation, and to use the caustic potash poured loose into a bag permeable to air. ,By adopting these measures a very simple and extremely compact i'orm of the apparatus is achieved; long respiratory passages with their known disadvantages are unnecessary, and at the same time the condition occurring in the known respirators with injector actionwhere there is a negative pressure in one part of the respiratory passages and in consequence harmful air from outside may be drawn in through any leakages inthe respiratory passages-is avoided.

The present invention accordingly provides an oxygen apparatus with closed respiratory circuit for use over short periods, having a mass giving oit a constant current of oxygen after being heated initially, in which the jet nozzle of an injector is connected I direct to the receptacle for the oxygen-generating mass, the mixing nozzle of said injector passing the gas mixture into the receptacle for the carbon dioxide-absorbing mass,` the suction chamber of said injector being connected either directlyor indirectly via the receptacle for the carbon dioxide-absorbing mass, with the respiratory pipe and the respiratory bag.

In order more clearly to understand the invention, reference is made to the accompanying drawings, which illustrate dagrammatically and by way of example, several embodiments thereof.

First embodiment 4 Fig. l. shows anoxygen-supplying device A havinga potash cartridge B attached thereto and an linjector C mounted thereon. y The. device A supplying the oxygen contain the oxygen generating compositionin the form of a compressed body vl) disposed in a thin sheet iron receptacle. E represents a cavity to hold an igniting composition. The oxygengenerating mass is separated lon all sides from the metal walls and from the base of the receptacle by a jacket of heat insulation and iiltering material, which consists for example lof barium hydroxide, impregnated pumice powder, asbestos, silica gel or the like. The top of the container is closed by a. lid,'preferably threefold, (F1, F2.' Fa). The lid-F2 carries the percussion cap G, on which the pointed percussion pin H is loosely mounted in a guide I. The thin lid F1, which can also be furnished with grooves, lies on the 'percussion pin H. The ignitionis effected by striking thelid F1, the blow being transmitted to the percussion pin H and igniting the percussion cap. Between the container A and the potash cartridge B is d isposed a sheet metal partition K at the centre ofiwhich is mounted the nozzle L of the injector C. Said injector projects into the potash cartridge in which are disposed wire sieves M to hold the caustic potash N. Two pipe connections Oi and O2 are provided at the opposite end of the potash cartridge oi which Oi is joined by the tube P to the mouthpiece or mask, whileOz carn ries the respiratory bag R. The mouthpiece, mask and the excess pressure valve are not shown in the drawings.

The method of working is as follows: After the generation ci oxygen from the mass D has been started, the oxygen passes under pressure out of thenozzle L, through the injector C and lis inhaled through the tube i or stored as surplus in the bag R. As a result of the injector action air is drawn out of the potash cartridge by the oxygen owing out at L and forced through the jet pump. The air drawn o is supplemented by fresh air containing carbon dioxide, so that there is a constant iiow through the potash cartridge and therefore absorption of the carbon dioxide.

Second embodiment Fig. 2 shows an oxygen-supplying device A, the construction oi which is the same as in Fig. 1. In 'contradistinction to the latter it is however not permanently attached to the potash cartridge B, but is screwed thereto. The screw coupling S carries in the middle the nozzle L which projects into the outer injector tube C. The lower extremity oi the latter is continued in the form o a funnel T furnished with apertures, which is surrounded by the material N absorbing the carbon dioxide; to hold the funnel T and material N use is made of asheath or casing U which is permeable to air. R. represents the respirator bag. O represents'the pipe connection to which the respiratory pipe leading to the mouthpiece or mask is attached. The pipe connection is divided by the partition V into two respiratory pipes O1 and O2.

The oxygen emerging from the device A supplying the oxygen, through the nozzle L, after said device A has been put into operation, draws the exhaled air through the pipes O1 and O into the carbon dioxide absorption' device and there forces it through the material` N and the sheath U into the respirator bag R, from which the re generated air is inhaled through 02 and 0.

Third embodiment placed on the perforated plate W which is permeable to airand enclosed in the sheath or casy ing U which is not permeable to air. R represents the respirator bag, O the respiratory pipe' connection, which is again divided into two respiratory pipes Oi and Oa by the partition V.

The oxygen emerging from A through the nozchemicals.

aioaaee zle L draws the exhaled air through the pipes O1 and O and .passes it through the funnel T into the chamber lled with the material N absorbing the carbon dioxide. After passing through this chamber the air, in this way made iit for breathing again, passes through 02 into lthe pipe O, from where it is inhaled.

i claim:- 1. An oxygen emergency apparatus with closed respiratory circuit comprising a gas chamber, a

chemical mixture adapted to generate oxygen on being initially heated disposed therein, an absorption chamber containing a chemical adapted to absorb carbon dioxide adjacent to said gas chamber, an injector device comprising a nozzle and a mixing tube surrounding-said nozzle and extending beyond the mouth thereof, projecting from' said gas chamber' into said absorptionlchamber, a duct for leading at least part of the air exhaled by the user into said absorption chamber, said duct being so disposed in relation to said injector nozzle as to enable -the oxygen passing through the latter to produce a suctlonal enect on the air passing through said duct, another duct leading away from saidnabsorption chamber. and a mouth piece connected with both said ducts and adapted to be tted to the mouth of the user.

2. An oxygen emergency apparatus with closed respiratory circuit comprising a gas chamber, a chemical mixture adapted to generate oxygen on being initially heated disposed therein, a perforated absorption chamber containing a chemical adapted to absorb carbon dioxide adjacent to said gas chamber, an injector device comprising a nozzle and a mixing tube surrounding said nozzle and extending beyond the mouth thereof, projecting from said gas chamber into said absorption chamber, the carbon dioxide absorbing chemical being disposed around said mixing tube, a respiratory bag surrounding said absorption chamber, a duct for leading at least part oi' the air exhaled by the user into said absorption chamber, said duct being so disposed in relation to said injector nozzle as to enable the oxygen passing through the latter to produce a' suctional eiect on the air passing through said duct, another duct leading away from said absorption chamber, and a mouth piece connected with both said d ucts and adapted to be fitted to the mouth of the user. l

3. An omgen emergency apparatus with a closed respiratory circ'uit comprising a gas chamber, means for generating oxygen in said chamber, a carbon dioxide absorption chamber adjacent said gas chamber, a nozzle attached to said gas chamber, a mixing tube surrounding and extending beyond the end oi said nozzle, means disi posed around said mix'ing tubefor holding carbon dioxide absorption chemicals, a duct for leading at least part of the air exhaled'by the user to a point adjacent the carbon dioxide absorption` chemicals, discharge of generated oxygen through said nozzle into said mixing tube causing a circulation of exhaled air throughsaid absorption mx yHausmann.v 

